where \(\bar{z} = {\left[ {\bar{b},\bar{\alpha }} \right]^T}\)  and \({R_{b\alpha }} = diag\left( {\sigma _b^2,\sigma _\alpha ^2} \right)\) . If the point \({z_m}\)  is converted into Cartesian coordinates as \({t_m} = {h^{ - 1}}\left( {{z_m}} \right)\) , then the converted PDF was given by [1]}
\({p_{xy}}\left( {{t_m}} \right) = \frac{{{p_{b\alpha }}\left( {h\left( {{t_m}} \right)} \right)}}{{\left|J\right|}}\) 
